This book represents a departure from Mark Mazower's previous work, some of which has explored Nazi policy and occupied Europe, as well as the history of the Balkans. In Governing the World, Mazower changes focus in both time and space to explore the idea of international governance. Although he does not offer an explicit thesis statement, Mazower aims to investigate the historical evolution of global governance to show how some ideas "have shaped realities through the institutions that they have inspired, and to ask what is left of them today." In so doing, he highlights that some of the ideas that currently govern American institutions have their origins in European affairs: "these ideas and institutions originated in Europe before spreading across the Atlantic and around the globe during the two centuries of Western world hegemony that are now drawing to a close."

To accomplish this objective, he divides the book into two sections, the first of which examines the ways in which the Great Powers of Europe reacted to the destructive consequences of the French Revolution and the Napoleonic Wars. The Concert of Europe (1815-1914), Mazower suggests, was a period during which the Great Powers ensured that no single hegemonic power operated freely. For Metternich and his contemporaries, the consequences of Napoleon's wars substantiated this. This was the era of internationalism.

The second part of the book, "Governing the World the American Way," shows how the ideas from continental Europe made their way to America following the First World War. Here, Mazower picks up where the first section ends: the eventual denouement of the League of Nations. It is not until the section exploring the geopolitical realities of the Cold War where he offers a much more explicit thesis statement. On page 231, Mazower writes "on the whole, as this book has attempted to make clear, world government in the sense espoused by Saint-Simon, H.G. Wells, or Paul Otlet has always been a minority taste. Believing in the compatibility of nationalism and internationalism, what most nineteenth-century internationalists sought was a coordinating agency that would empower nation-state members." Throughout the book, therefore, Mazower demonstrates the inherent problems in the reconciliation of nationalism and the desire for international governance. At the crux of his argument is the constant struggle between ideas of internationalism versus their application in practice.

This book is meticulously researched and offers much to readers interested in international relations, European politics, and historians. Perhaps more importantly, Mazower contributes to the history of ideas relating to global governance and has written a lucid history of how those ideas have dictated the development of international institutions. If one offers any criticism of the book, it would be that some chapters appear disjointed within the broader narrative. For example, Chapter 4 "Science the Unifier", provides an overview of international contributions to science, such as Otlet's development of statistics (which, though not mentioned, was greatly influenced by Auguste Comte) and Ludwig Zamenhof's creation of Esperanto as a universal language. As one of the shorter chapters, it lacks an adequate appreciation for the divisive nature that science had on European societies. While some members of the European scientific community were drawn to the benefits of internationalism, the impact of Darwin's theory of evolution, for instance, had terrible and unintended consequences, as Europeans and non-whites became increasingly categorized into "types." This had an enormous impact on criminology and sociology among many other disciplines. Cesare Lombroso applied these scientific principles to determine which types of people were atavistic criminals. Suffice it to say that while science had the propensity to unify, it also had the tendency to substantiate claims of supremacy over other peoples.

Despite these criticisms, the book still offers a great deal of information and detail one would expect of Mark Mazower